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Abstract:

A high-frequency treatment instrument of the present invention includes:
a pair of forceps members that includes a conductive electrode portion
and an insulating portion and is supported by the forceps rotation shaft
so as to be relatively rotatable; an operation section configured to open
and close the pair of forceps members; a link mechanism that is attached
to the pair of forceps members and includes a pair of link members; an
operation wire that connects the link mechanism to the operation section;
a rotation contact member that is rotatably connected to the pair of
forceps members; and a regulation wire in which one end thereof is
electrically connected to the rotation contact member, a part of an
intermediate portion thereof is disposed so as to pass through a space
between the respective link members, and the other end thereof is
electrically connected to a power supply.

Claims:

1. A high-frequency treatment instrument comprising: a pair of forceps
members that includes a conductive electrode portion and an insulating
portion and is supported by a rotation shaft so as to be relatively
rotatable; an operation section configured to open and close the pair of
forceps members; a link mechanism that is attached to the pair of forceps
members and includes a pair of link members configured to rotate the
respective forceps members around the rotation shaft; an operation wire
that connects the link mechanism to the operation section; a rotation
contact member that is rotatably connected to the pair of forceps members
around the rotation shaft and is formed of a conductive member; and a
power feeding wire in which one end thereof is electrically connected to
the rotation contact member, a part of an intermediate portion thereof is
disposed so as to pass through a space between the respective link
members, and the other end thereof is electrically connected to a power
supply capable of supplying electric power.

2. A high-frequency treatment instrument comprising: a pair of forceps
members, in which each of the forceps members includes a conductive
electrode portion and an insulating portion and is supported by a
rotation shaft so as to be relatively rotatable; an operation section
configured to open and close the pair of forceps members; a link
mechanism that is attached to the pair of forceps members and includes a
pair of link members configured to rotate the respective forceps members
around the rotation shaft; an operation wire that connects the link
mechanism to the operation section; a rotation contact member that is
rotatably connected to the pair of forceps members around the rotation
shaft and is formed of a conductive member; and a power feeding wires in
which one end thereof is electrically connected to the rotation contact
member, a part of an intermediate portion thereof is disposed so as to
pass through a space between the respective link members, and the other
end thereof is electrically connected to a power supply capable of
supplying electric power, wherein the pair of forceps members is
supported so that the respective electrode portions are insulated from
each other by the insulating portion interposed between the respective
electrode portions in the axial direction of the rotation shaft.

3. The high-frequency treatment instrument according to claim 1, wherein
the link mechanism includes a connection member provided with a groove
which extends in parallel to the axis of the operation wire, the power
feeding wire is disposed adjacent to the operation wire so as to be
parallel to the operation wire in the side of operation section from the
connection member, and the connection member guides the power feeding
wire to the rotation contact member so as to separate the power feeding
wire from the operation wire by disposing the power feeding wire inside
the groove.

4. The high-frequency treatment instrument according to claim 2, wherein
the link mechanism includes a connection member provided with a groove
which extends in parallel to the axis of the operation wire, the power
feeding wire is disposed adjacent to the operation wire so as to be
parallel to the operation wire in the side of operation section from the
connection member, and the connection member guides the power feeding
wire to the rotation contact member so as to separate the power feeding
wire from the operation wire by disposing the power feeding wire inside
the groove.

5. The high-frequency treatment instrument according to claim 1, wherein
the electrode portion and the first end portion of the power feeding wire
are arranged so that at least a part of the electrode portion and the
first end portion overlap each other when seen from the axial direction
of the operation wire.

6. The high-frequency treatment instrument according to claim 2, wherein
the electrode portion and the first end portion of the power feeding wire
are arranged so that at least a part of the electrode portion and the
first end portion overlap each other when seen from the axial direction
of the operation wire.

7. The high-frequency treatment instrument according to claim 1, wherein
the rotation shaft includes a core body and an insulating layer that
coats an outer peripheral surface of the core body.

8. The high-frequency treatment instrument according to claim 7, wherein
the insulating layer is configured as a cylindrical insulating member
formed of an insulating material, and the insulating member includes a
projecting portion that projects in the direction separating from the
axis of the core body while being attached to the core body.

9. The high-frequency treatment instrument according to claim 2, wherein
the rotation shaft includes a core body and an insulating layer that
coats an outer peripheral surface of the core body.

10. The high-frequency treatment instrument according to claim 9, wherein
the insulating layer is configured as a cylindrical insulating member
formed of an insulating material, and the insulating member includes a
projecting portion that projects in the direction separating from the
axis of the core body while being attached to the core body.

Description:

[0001] This application is a continuation application based on a PCT
Patent Application No. PCT/JP2010/063393, filed Aug. 6, 2010, whose
priority is claimed on Japanese Patent Application No. 2009-212945, filed
on Sep. 15, 2009, the contents of both the PCT Application and the
Japanese Application are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a high-frequency treatment
instrument that is endoscopically inserted into a body cavity and is used
by means of a high-frequency current supplied thereto.

[0004] 2. Description of Related Art

[0005] Hitherto, there is a known treatment instrument for an endoscope
(hereinafter, simply referred to as a `treatment instrument`) that
performs various therapeutic techniques on tissue inside a body cavity of
a patient or the like while being endoscopically inserted into the body
cavity.

[0006] One type of the treatment instrument performs a treatment on target
tissue using electric energy by means of a high-frequency current
supplied to a treatment section in a distal end thereof, and is generally
called a high-frequency treatment instrument (for example, see Japanese
Patent (Granted) Publication No. 4197983).

[0007] In the high-frequency treatment instrument disclosed in the above
patent document, a pair of forceps members supported through a rotation
shaft so as to be relatively rotatable is installed at the distal end as
the treatment section. The pair of forceps members is connected to an
operation section on the hand side through an operation wire.

[0008] In many cases, the operation wire is formed of a conductor such as
metal. For this reason, as a general configuration of the high-frequency
treatment instrument, an operation wire is connected to a high-frequency
power supply, and a high-frequency current is supplied to a treatment
section such as a forceps member through the operation wire.

SUMMARY OF THE INVENTION

[0009] According to an aspect of the present invention, a high-frequency
treatment instrument including: a pair of forceps members that includes a
conductive electrode portion and an insulating portion and is supported
by a rotation shaft so as to be relatively rotatable; an operation
section configured to open and close the pair of forceps members; a link
mechanism that is attached to the pair of forceps members and includes a
pair of link members configured to rotate the respective forceps members
around the rotation shaft; an operation wire that connects the link
mechanism to the operation section; a rotation contact member that is
rotatably connected to the pair of forceps members around the rotation
shaft and is formed of a conductive member; and a power feeding wire in
which one end thereof is electrically connected to the rotation contact
member, a part of an intermediate portion thereof is disposed so as to
pass through a space between the respective link members, and the other
end thereof is electrically connected to a power supply capable of
supplying electric power.

[0010] In addition, according to another aspect of the invention, a
high-frequency treatment instrument including: a pair of forceps members,
in which each of the forceps members includes a conductive electrode
portion and an insulating portion and is supported by a rotation shaft so
as to be relatively rotatable; an operation section configured to open
and close the pair of forceps members; a link mechanism that is attached
to the pair of forceps members and includes a pair of link members
configured to rotate the respective forceps members around the rotation
shaft; an operation wire that connects the link mechanism to the
operation section; a rotation contact member that is rotatably connected
to the pair of forceps members around the rotation shaft and is formed of
a conductive member; and a power feeding wires in which one end thereof
is electrically connected to the rotation contact member, a part of an
intermediate portion thereof is disposed so as to pass through a space
between the respective link members, and the other end thereof is
electrically connected to a power supply capable of supplying electric
power. Furthermore, the pair of forceps members is supported so that the
respective electrode portions are insulated from each other by the
insulating portion interposed between the respective electrode portions
in the axial direction of the rotation shaft.

[0011] The link mechanism may include a connection member provided with a
groove which extends in parallel to the axis of the operation wire. The
power feeding wire may be disposed adjacent to the operation wire so as
to be parallel to the operation wire in the side of operation section
from the connection member. The connection member may guide the power
feeding wire to the rotation contact member so as to separate the power
feeding wire from the operation wire by disposing the power feeding wire
inside the groove.

[0012] The electrode portion and the first end portion of the power
feeding wire may be arranged so that at least a part of the electrode
portion and the first end portion overlap each other when seen from the
axial direction of the operation wire.

[0013] The rotation shaft may include a core body and an insulating layer
that coats the outer peripheral surface of the core body.

[0014] The insulating layer may be configured as a cylindrical insulating
member formed of an insulating material, and the insulating member
includes a projecting portion that projects in the direction separating
from the axis of the core body while being attached to the core body.

BRIEF DESCRIPTION OF THE DRAWING

[0015] FIG. 1 is an entire diagram of a treatment instrument for an
endoscope in a first embodiment of the present invention.

[0016] FIG. 2 is a diagram showing the periphery of a treatment section of
the treatment instrument for the endoscope except a cover.

[0017]FIG. 3 is a cross-sectional view taken along the line B-B of FIG.
2.

[0018] FIG. 4 is a cross-sectional view of the periphery of the treatment
section.

[0019]FIG. 5 is a cross-sectional view taken along the line A-A of FIG.
2.

[0020] FIG. 6 is a cross-sectional view showing a part of an insertion
section of the treatment instrument for the endoscope.

[0021]FIG. 7 is a diagram showing an operation when the treatment
instrument for the endoscope is used.

[0022]FIG. 8 is a diagram showing the periphery of a treatment section of
a treatment instrument for an endoscope in a third embodiment of the
present invention except a cover.

[0023]FIG. 9 is a cross-sectional view taken along the line C-C of FIG.
8.

[0024]FIG. 10 is a cross-sectional view of the periphery of the treatment
section.

[0025] FIG. 11 is a cross-sectional view showing a part of an insertion
section in a treatment instrument for an endoscope of a modified example
of the present invention.

[0026]FIG. 12 is a cross-sectional view of a connection section in a
treatment instrument for an endoscope of a modified example of the
present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, referring to FIGS. 1 to 6, a treatment instrument for
an endoscope in a first embodiment of the present invention will be
described. As shown in FIG. 1, a high-frequency treatment instrument 51
in the present embodiment includes a treatment section 60 which is
configured to perform a treatment on tissue inside a body cavity, an
operation section 20 which is configured to operate the treatment section
60, a connection section 30 which is configured to connect the treatment
section 60 to the operation section 20, and an elongated insertion
section 40 which is inserted into the body cavity.

[0028] The treatment section 60 is configured such that a pair of forceps
members including a first forceps member 61 and a second forceps member
62 is supported by a forceps rotation shaft (a rotation shaft) 65 so as
to be relatively rotatable to each other. The forceps rotation shaft 65
is supported by a cover 14 which is disposed so as to interpose the
forceps members 61 and 62 therein.

[0029] FIG. 2 is a diagram showing the periphery of the treatment section
60 of the high-frequency treatment instrument 51 except the cover 14. The
second forceps member 62 is formed of a ceramic member such as alumina or
zirconia or a resin such as polytetrafluoroethylene (PTFE) or polyether
ether ketone (PEEK: registered trademark), and has an insulating
property.

[0030] Furthermore, instead of such a configuration, the second forceps
member 62 may be formed by coating an entire surface of a core formed of
metal such as stainless steel or the like with the above-described
insulating member, an insulating coating, or the like.

[0031] On the other hand, the first forceps member 61 includes an
electrode portion 63 in which an electrode surface 63A thereof formed of
a conductor such as stainless steel or the like is exposed and an
insulating portion 64 which is placed so as to coat a part of the
electrode portion 63. As shown in FIG. 2, it is desirable to provide the
electrode surface 63A on at least an opening and closing surface which
comes into contact with tissue inside a body cavity during a treatment
and in which the pair of forceps members 61 and 62 face each other.
Further, it is desirable that the area of the electrode surface 63A is
small so that energy may be more easily concentrated.

[0032] The insulating portion 64 can be formed by performing a coating or
an insulating coating on a part of the surface of the electrode portion
63 using the same insulating member as that of the second forceps member
62. The insulating portion 64 is placed so as to coat all portions of the
electrode portion 63 having a possibility of coming into contact with,
for example, the respective members of the connection section 30 to be
described later or the cover 14 so that the current supplied to the
electrode portion 63 does not leak to a metal portion such as the
treatment section 60 and the connection section 30 and the like. Thus, in
the first forceps member 61, almost all surfaces of the portion
positioned at the base end side in relation to the forceps rotation shaft
65 to be described later are coated by the insulating portion.

[0033]FIG. 3 is a cross-sectional view taken along the line B-B of FIG.
2. As shown in FIG. 3, the forceps rotation shaft 65 connects the forceps
members 61 and 62 to each other so as to be relatively rotatable. The
forceps rotation shaft 65 includes a core body 66 formed of a conductor
and a cylindrical portion (an insulating layer) 67 which coats the outer
peripheral surface of the core body 66 for the purpose of insulation
thereof. The cylindrical portion 67 may be formed as a member using an
insulating material, or as an insulating layer using an insulating
coating or the like.

[0034] Returning to FIG. 1, the operation section 20 includes a main body
21 to which the insertion section 40 is attached and a slider 52 which is
slidably attached to the main body 21. The slider 52 is provided with a
plug 53 which is connected to a high-frequency power supply (not shown).

[0035] The slider 52 and the treatment section 60 are connected to each
other by the connection section 30, and the pair of forceps members 61
and 62 can be opened and closed by sliding the slider 52 in the
longitudinal direction of the main body 21. This point will be
specifically described in the description of the operation in use.

[0036] FIG. 4 is a cross-sectional view of the periphery of the treatment
section 60 which is seen from a different angle (the direction orthogonal
to both the forceps rotation shaft 65 and the axis X1 of an operation
wire 31). As shown in FIGS. 2 and 4, the connection section 30 includes
the operation wire 31, a link mechanism 32 which is attached to the
distal end of the operation wire 31, and a regulation wire (a regulation
portion) 71 which guides reciprocating operation of the link mechanism
32. The operation wire 31 has a known configuration, where a first end
portion 31A positioned at the distal end side thereof is connected to the
link mechanism 32 and a second end portion 31B (see FIG. 1) positioned at
the base end side thereof is connected to the slider 52 of the operation
section 20.

[0037] The link mechanism 32 includes a connection member 34 which is
attached to the distal end of the operation wire 31, and a first link
member 35 and a second link member 36, as a pair of link members, used to
connect the connection member 34 to the pair of forceps members 61 and 62
respectively.

[0038] The connection member 34 includes two link rotation shafts 34A and
34B which are provided at the distal end side thereof. The respective
base ends of the first link member 35 and the second link member 36 are
connected to the link rotation shafts 34A and 34B through pins 37 so as
to be rotatable. Further, the connection member 34 is provided with a
groove 34C which extends in parallel to the axis X1 of the operation wire
31.

[0039] The respective link rotation shafts 34A and 34B are spaced from the
axis X1 of the operation wire 31 by the same distance (also substantially
the same distance), and face each other with the axis X1 interposed
therebetween. The axes of two pins 37 are parallel (also substantially
parallel) to each other, and two link rotation shafts 34A and 34B are
disposed so as to be parallel to each other.

[0040] The respective distal end sides of the link members 35 and 36 are
connected to the base end sides of the first forceps member 61 and the
second forceps member 62 so as to be rotatable. The positions of the
respective link members 35 and 36 are set so as to be parallel to each
other while the pair of forceps members 61 and 62 is closed.

[0041] The base end side (the second end portion) of the regulation wire
71 is electrically connected to the plug 53 of the operation section 20
through the insertion section 40, and the regulation wire 71 also serves
as a power feeding wire which supplies a high-frequency current to the
electrode portion 63 of the treatment section 60. The regulation wire 71
is provided with an insulating coating 72 throughout the substantially
entire length thereof except both end portions so that a current does not
leak to any metal portion except the electrode portion 63. Further, the
regulation wire 71 is disposed in parallel (also substantially parallel)
to the axis X1 of the operation wire 31 so as to pass inside the groove
34C of the connection member 34.

[0042] A cylindrical rotation contact member 73 is provided on the distal
end (the first end portion) of the regulation wire 71. As shown in FIG.
3, the rotation contact member 73 is fitted to the outside of the
cylindrical portion 67 so as to be coaxial with the forceps rotation
shaft 65. The rotation contact member 73 is electrically connected to a
part of the electrode portion 63 which is exposed so as to face the outer
peripheral surface of the cylindrical portion 67.

[0043] As shown in FIG. 4, a part of the electrode portion 63 is disposed
so as to be able to come into contact with the rotation contact member 73
at each of both sides of the rotation contact member 73 in the direction
of the axis X1. That is, the rotation contact member 73 and the electrode
portion 63 are arranged with a positional relationship in which at least
a part of the rotation contact member 73 and a part of the electrode
portion 63 overlap each other when seen in the direction of the axis X1.

[0044] With the above-described structure, the distal end of the
regulation wire 71 is attached to the forceps rotation shaft 65 so as to
be rotatable relative to the forceps rotation shaft 65, and is configured
to supply a high-frequency current only to the electrode portion 63 of
the first forceps member 61. Further, as shown in FIG. 2, the regulation
wire 71 is disposed so as to be positioned between the first link member
35 and the second link member 36 when seen in the axial direction of the
link rotation shafts 34A and 34B. That is, the regulation wire 71 and the
respective link members 35 and 36 have a positional relationship in which
they do not overlap each other when seen in the axial direction.

[0045] With the above-described respective structures, the high-frequency
treatment instrument 51 is configured to serve as a monopolar (monopole
type) high-frequency treatment instrument as a whole.

[0046]FIG. 5 is a cross-sectional view taken along the line A-A of FIG.
2. As shown in FIG. 5, the cross-sectional shape of the connection member
34 in the plane orthogonal to the axis X1 is formed in a crank shape so
that the portion provided with the link rotation shaft 34A and the
portion provided with the link rotation shaft 34B are alternatively
placed in relation to the axis X1 interposed therebetween. Accordingly,
in either of the link rotation shafts 34A and 34B, the maximal value of
the thickness of the link mechanism 32 is substantially equal to the sum
of the thickness of the connection member 34 and the thicknesses of the
link member 35, or is substantially equal to the sum of the thickness of
the connection member 34 and the thicknesses of the link member 36. That
is, the maximal value is suppressed to be a thickness corresponding to
the two members.

[0047] As shown in FIG. 2, the insertion section 40 includes a coil sheath
41 through which the operation wire 31 is inserted and a tube sheath 42
through which the coil sheath 41 is inserted.

[0048] With regard to the coil sheath 41, variously known members may be
appropriately selected and adopted. The cover 14 is attached to the
distal end of the coil sheath 41, and the base end of the coil sheath 41
is fixed to the main body 21 of the operation section 20.

[0049] As shown in FIG. 6, the coil sheath 41 is provided with a small
diameter portion 43 with a small outer diameter. The small diameter
portion 43 is formed by performing a cutting process or the like on the
outer peripheral surface of the coil sheath 41. The small diameter
portion 43 is placed in the base end side portion away from the distal
end of the coil sheath 41 by a predetermined length L1. The coil sheath
41 is divided into two parts at the small diameter portion 43, and an
integral coil sheath is obtained by fixing a connection ring 44 attached
to the small diameter portion 43 by a method such as soldering or the
like.

[0050] Also with regard to the tube sheath 42, variously known members
formed of a resin or the like may be appropriately selected and adopted.
The base end of the tube sheath 42 is inserted into an opening provided
at the distal end of the main body 21, but is relatively rotatable with
respect to the main body 21. A ring member (a reciprocation regulating
member) 45 which is fitted to the small diameter portion 43 of the coil
sheath 41 is press-inserted into the tube sheath 42. In the
press-inserted state, the inner diameter of the ring member 45 is set to
be smaller than either of the basic outer diameter of the coil sheath 41
(the outer diameter of the portion other than the small diameter portion
43) and the outer diameter of the connection ring 44. Further, the inner
diameter of the ring member 45 is larger than the outer diameter of the
small diameter portion 43, and a clearance is ensured therebetween.

[0051] With such a configuration, the coil sheath 41 and the tube sheath
42 are configured to be relatively rotatable to each other around the
axis and to be not substantially relatively movable to each other in the
axial direction. In order to realize the above-described configuration,
one coil sheath provided with the small diameter portion 43 is divided
into two parts by cutting the coil sheath at the small diameter portion
43. Then, the cut coil sheaths are connected as one part by using the
connection ring 44 while the ring member 45 is fitted into the small
diameter portion of the cut coil sheath of a distal end side.
Subsequently, when the coil sheath 41 to which the ring member 45 is
attached is inserted into the tube sheath 42 and the ring member 45 is
press-inserted into the tube sheath 42, the insertion section 40 of the
high-frequency treatment instrument 51 is completed.

[0052] The predetermined length L1 may be appropriately set. But it is
desirable to set the length, for example, 20 mm or more, in which the
insertion section 40 between the connection member 34 of the connection
section 30 and the ring member 45 is sufficiently bendable in order to
substantially shorten the length of a rigid portion (described later) in
the distal end side of the high-frequency treatment instrument 51.

[0053] The operation in use of the high-frequency treatment instrument 51
with the above-described configuration will be described.

[0054] First, an endoscope (not shown) is inserted into a body cavity of a
patient who comes into contact with a known return electrode (not shown),
and the distal end of the endoscope is made to advance to the vicinity of
tissue (target tissue) inside a body cavity of a treatment target.

[0055] Subsequently, the slider 52 is retracted with respect to the main
body 21 of the operation section 20 so that the pair of forceps members
61 and 62 is closed, and the insertion section 40 is inserted into a
forceps channel of the endoscope. Then, the treatment section 60 is
projected from the distal end of the forceps channel. At this time, since
the treatment section 60 disposed at the distal end of the high-frequency
treatment instrument 51 and a part of the connection section 30 covered
by the cover 14 are away from the portion of the insertion section 40
provided with the ring member 45 by the predetermined length L1, the
insertion section 40 positioned therebetween maintains its flexibility.
As a result, even when the endoscope is disposed in a meandering shape or
the like inside the body cavity, the insertion section 40 can be
satisfactorily bent in accordance with the shape of the endoscope, and
the high-frequency treatment instrument 51 can be appropriately inserted
into the forceps channel of the endoscope.

[0056] After the treatment section 60 is projected from the forceps
channel, a user connects a high-frequency power supply (not shown) to the
plug 53 through a power supply cable (not shown).

[0057] When a treatment is performed, the slider 52 is moved forward with
respect to the main body 21. Then, the operation wire 31 connected to the
slider 52 advances with respect to the coil sheath 41. As described
above, since the forceps rotation shaft 65 is supported by the cover 14
which is attached to the coil sheath 41, the first forceps member 61 and
the second forceps member 62 respectively rotate around the forceps
rotation shaft 65, so that the treatment section 60 is opened as shown in
FIG. 7.

[0058] At this time, the operation wire 31 and the connection member 34
attached to the distal end thereof advance and retract along the
regulation wire 71 which is disposed in parallel to the axis X1 of the
operation wire 31 by allowing the groove 34C to engage with the
regulation wire 71. Accordingly, the operation wire 31 and the connection
member 34 are regulated in the relative movement direction with respect
to the forceps rotation shaft 65, and the connection member 34 is
operated to advance and retract while being suppressed from being
deviated in the direction separating from the axis X1. As a result, the
pair of forceps members 61 and 62 is satisfactorily opened and closed.

[0059] The user performs a desired treatment on target tissue while the
pair of forceps members 61 and 62 of the treatment section 60 is opened
and closed by sliding the slider 52. If necessary, the treatment section
60 may be rotated by rotating the main body 21 around the axis thereof so
as to adjust a positional relationship between opening and closing
surfaces of the pair of forceps members 61 and 62 and the target tissue.

[0060] When the user positions the target tissue between the pair of
opened forceps members 61 and 62 of the treatment section 60 and pulls
the slider 52 in the direction separating from the treatment section 60,
the respective distal end sides of the pair of forceps members 61 and 62
are closed, so that the target tissue is nipped in the treatment section
60 and the electrode surface 63A comes into contact with the target
tissue. In this state, when the user supplies a high-frequency current
from the high-frequency power supply, the high-frequency current is
supplied to the electrode portion 63 through the regulation wire 71, and
the target tissue is cauterized at the electrode surface 63A.

[0061] After the completion of the treatment, the user extracts the
high-frequency treatment instrument 51 from the forceps channel, extracts
the endoscope to the outside of the body, and finishes the therapeutic
technique.

[0062] According to the high-frequency treatment instrument 51 of the
present embodiment, the regulation wire 71 is used as the power feeding
wire. For this reason, compared to the case of the power feeding
operation through the operation wire 31, an insulating may not be
performed on the respective link members 35 and 36 and the like and the
high-frequency current can be more easily and selectively supplied to the
electrode portion 63. As a result, a power feeding structure can be
realized in which energy more easily concentrates on the electrode
surface 63A used for the treatment.

[0063] Further, since the distal end of the regulation wire 71 is
connected to the forceps rotation shaft 65 so as to be relatively
rotatable through the rotation contact member 73, no extra force is
applied to the pair of forceps members 61 and 62 when the forceps members
are opened and closed, and the forceps members can be appropriately
opened and closed.

[0064] Furthermore, since the rotation contact member 73 does not move
according to the operation in which the pair of forceps members 61 and 62
is opened and closed, the rotation contact member 73 is not exposed to
the outside of the cover 14 during a treatment or the like. Accordingly,
it is possible to appropriately prevent the regulation wire 71 from
unnecessarily coming into contact with tissue inside a body cavity and
leakage of electricity.

[0065] Furthermore, since the rotation contact member 73 is fitted to the
outside of the cylindrical portion 67 of the forceps rotation shaft 65,
the rotation contact member 73 is interposed between the cylindrical
portion 67 and the electrode portion 63 which is exposed so as to face
the outer peripheral surface of the cylindrical portion 67, and a part of
the electrode portion 63 is disposed at each of both sides of the
rotation contact member 73 in the direction of the axis X1. Accordingly,
when the slider 52 is pulled to be away from the treatment section 60 so
as to close the pair of forceps members 61 and 62 during a treatment, the
regulation wire 71 is also pulled toward the operation section 20. In
accordance with this operation, the rotation contact member 73 is also
pulled toward the operation section 20 and is pressed against a part of
the electrode portion 63. Accordingly, the rotation contact member 73
reliably comes into contact with the electrode portion 63, so that the
high-frequency current can be supplied therethrough during a treatment.

[0066] Furthermore, the forceps rotation shaft 65 includes the core body
66 which is formed of a conductor such as metal and the cylindrical
portion 67 which coats the outer peripheral surface of the core body 66
for the purpose of insulating thereof. Accordingly, the forceps rotation
shaft 65 can easily ensure rigidity to sufficiently withstand a force
applied thereto when the pair of forceps members 61 and 62 is operated to
be opened and closed, while the insulation between the forceps rotation
shaft 65 and the electrode portion 63 is maintained.

[0067] Further, since the regulation wire 71 serving as the power feeding
wire and the pair of link members 35 and 36 are arranged so as not to
overlap each other when seen from the axial direction of the link
rotation shafts 34A and 34B, the regulation wire 71 can be disposed so as
to pass between the pair of link members 35 and 36 arranged in parallel
to each other and to have a linear shape parallel to the axis X1 of the
operation wire 31. As a result, the regulation wire 71 can be
appropriately equipped with both a function of guiding a sliding movement
of the connection member 34 of the connection section 30 and a function
of feeding power to the electrode portion 63.

[0068] Furthermore, the connection member 34 is provided with two link
rotation shafts 34A and 34B which are spaced from the axis X1 of the
operation wire 31, and the link rotation shafts 34A and 34B are connected
to the first link member 35 and the second link member 36 respectively.
Accordingly, the thickness of the connection portion of the connection
member 34 and the respective link members 35 and 36 in the extension
direction in which the respective link rotation shafts 34A and 34B extend
is equal to the thickness corresponding to the sum of the connection
member 34 and either of the link members 35 and 36 in all longitudinal
range thereof. As a result, compared to an existing structure in which
two link members are connected to one rotation shaft, the distal end side
portion including the treatment section can be further decreased in
diameter.

[0069] Further, the rigid treatment section 60 and a part of the
connection section 30 which are provided at the distal end of the
high-frequency treatment instrument 51 are arranged so as to be away by
the predetermined length L1 from the ring member 45 which relatively
rotatably connects the coil sheath 41 and the tube sheath 42 in the
insertion section 40. For this reason, when the rigid treatment section
60 and the like are near the ring member 45, the length of the distal end
side rigid portion of the treatment instrument 1 which corresponds to the
sum of the lengths thereof in the axial direction can be substantially
shortened. Accordingly, a high-frequency treatment instrument which has a
satisfactory insertion property into the endoscope can be obtained.

[0070] In an existing high-frequency treatment instrument, the structure
to relatively rotatably connect the coil sheath 41 to the tube sheath 42
is provided near the distal end of the tube sheath in many cases. As a
result, there are problems in that the length of the distal end side
rigid portion is long, the high-frequency treatment instrument is not
easily inserted into the forceps channel, and large force is needed to
insert and extract the high-frequency treatment instrument into and from
the endoscope. The structure of the insertion section 40 of the
high-frequency treatment instrument 51 of this embodiment solves these
problems.

[0071] Next, the second embodiment of the present invention will be
described by referring to FIGS. 8 to 10. A high-frequency treatment
instrument 81 of this embodiment is different from the high-frequency
treatment instrument 51 of the above-described first embodiment in that
the high-frequency treatment instrument 81 is formed as a bipolar (dipole
type) high-frequency treatment instrument as a whole.

[0072] Furthermore, in the description below, the repetitive description
will be omitted by giving the same reference signs to the components
similar to those of the high-frequency treatment instrument 51 of the
first embodiment.

[0073]FIG. 8 is a diagram showing the periphery of a treatment section 90
of a treatment instrument 81 except the cover 14, and FIG. 9 is a
cross-sectional view taken along the line C-C of FIG. 8. Further, FIG. 10
is a cross-sectional view of the periphery of the treatment section 90 in
the plane parallel to both the forceps rotation shaft and the operation
wire. As shown in FIGS. 8 to 10, in the treatment instrument 81, two
regulation wires 71 which also serve as the power feeding wire are
connected to the treatment section 90. In accordance with this, the
groove 34C is also provided on each of both sides of the connection
member 34.

[0074] The treatment section 90 includes a pair of forceps members which
serves as the first forceps member 61 and a second forceps member 91. The
second forceps member 91 has the substantially same structure as that of
the first forceps member 61, and includes an electrode portion 92 with an
electrode surface 92A and an insulating portion 93. The contact portions
of the first forceps member 61 and the second forceps member 91 are
respectively coated by the insulating portions 64 and 93 so as not to be
electrically connected to each other. For example, the insulating portion
64 of the first forceps member 61 and the insulating portion 93 of the
second forceps member 91 are interposed between the electrode portion 63
of the first forceps member 61 and the electrode portion 92 of the second
forceps member 91 along the axial direction of a forceps rotation shaft
94 to be described later. Accordingly, the pair of forceps members 61 and
91 is supported so as to be relatively rotatable to each other through
the forceps rotation shaft 94 while the insulation thereof is ensured.

[0075] The forceps rotation shaft 94 includes the core body 66 and an
insulating cylindrical portion 95. The outer peripheral surface of the
cylindrical portion 95 is provided with a flange (a projecting portion)
96 which protrudes outward in the radial direction throughout the entire
circumference. Each of the first forceps member 61 and the second forceps
member 91 which are connected to the forceps rotation shaft 94 is
provided with a notch in a facing surface to each other, and the flange
96 enters a concave portion 97 which is formed of the notches.

[0076] A rotation contact member 82 which is attached to two regulation
wires 71 has the substantially same shape as that of the rotation contact
member 73 of the first embodiment, but the length of the cylindrical
portion which is fitted to the outside of the forceps rotation shaft 94
in the axial direction is set to be shorter than that of the rotation
contact member 73. As shown in FIGS. 8 and 10, one regulation wire 71A is
electrically connected to the electrode portion 92 of the second forceps
member 91, and the other regulation wire 71B is electrically connected to
the electrode portion 63 of the first forceps member 61. The respective
base ends of the regulation wires 71A and 71B are connected to a
high-frequency power supply (not shown), and form a high-frequency
current circuit.

[0077] The method of using the high-frequency treatment instrument 81 is
the same as that of the general bipolar high-frequency treatment
instrument, and the installation of the return electrode is not needed.
When the user nips the target tissue between the pair of forceps members
61 and 91 and supplies power to the treatment section 90, a
high-frequency current flows from the electrode surface (for example, the
electrode surface 63A) of one forceps member to the electrode surface
(for example, the electrode surface 92A) of the other forceps member, so
that the target tissue is cauterized.

[0078] In the high-frequency treatment instrument 81 of this embodiment,
the same effects as that of the high-frequency treatment instrument 51 of
the first embodiment can be also obtained, and a current-carrying
treatment can be performed while the pair of forceps members is
appropriately opened and closed.

[0079] Furthermore, the flange 96 is provided on the cylindrical portion
95 of the forceps rotation shaft 94, and the facing surfaces of the pair
of forceps members 61 and 91 are provided with the concave portion 97.
Accordingly, since the lateral distance of the member which is interposed
between the electrode portion 63 of the first forceps member 61 and the
electrode portion 92 of the second forceps member 91 becomes longer, a
further reliable insulation can be performed therebetween.

[0080] As described above, the respective embodiments of the present
invention have been described, but the technical scope of the invention
is not limited to the above-described respective embodiments, and may be
modified into various forms without departing from the technical scope.

[0081] For example, in the above-described respective embodiments, an
example has been described in which the small diameter portion 43 is
provided on the coil sheath 41 and the ring member 45 is attached to the
small diameter portion 43 so that the coil sheath 41 and the tube sheath
42 are relatively rotatable and are not relatively movable in the axial
direction. This structure has an advantage in that the coil sheath and
the tube sheath can be assembled without increasing the diameter of the
insertion section. However, instead of this structure, as shown in the
modified example of FIG. 11, a stopper ring 46 which has an outer
diameter larger than the inner diameter of the ring member 45A which is
press-inserted into the tube sheath 42 may be attached to the outer
periphery of the coil sheath 41 by soldering or the like so as to be
positioned at each of both sides of the axial direction of the ring
member 45A without forming the small diameter portion in the coil sheath
41.

[0082] In this way, the diameter of the portion to which the ring member
45A or the stopper ring 46 is attached increases compared to the case of
forming the small diameter portion. However, in the case of the treatment
instrument or the like which is less restricted in the diameter, there
are advantages in that the coil sheath 41 does not need to be cut and the
coil sheath 41 and the tube sheath 42 can be easily assembled with a
small number of processes.

[0083] Furthermore, in this case, a configuration may be adopted in which
the dimensional relationship between the ring member 45A and the stopper
ring 46 is reversed, the stopper ring 46 is press-inserted into the tube
sheath, and the ring member 45A is fixed to the coil sheath 41.

[0084] Further, in the above-described respective embodiments, an example
has been described in which a regulation portion that regulates the
rotation of the connection member around the axis is formed of the
regulation wire. In the case where the regulation wire is not used as the
power feeding wire, instead of this configuration, as shown in the
modified example of FIG. 12, a protrusion 14A may be formed on the cover
14 so as to protrude toward the connection member 34, and the protrusion
14A may engage with the groove 34C of the connection member 34 so as to
regulate the rotation of the connection member and the operation wire
around the axis.

[0085] At this time, a pair of the protrusion 14A and the groove 34A may
be, of course, provided only at one side.

[0086] Furthermore, the shape of the connection member which is provided
at the distal end of the operation wire is also not limited to that of
the above-described respective embodiments. For example, one link
rotation shaft may be provided and the respective base ends of the pair
of link members may be connected to the link rotation shaft.

[0087] Further, the pair of link members connected to two link rotation
shafts may be arranged so as to intersect each other while the pair of
forceps members is closed.

[0088] Furthermore, the structures and the configurations of the
above-described respective embodiments may be appropriately combined with
each other.

[0089] According to the present invention, a high-frequency treatment
instrument with a power feeding structure capable of easily concentrating
energy can be provided.